What Is a Sun Allergy?
Sun allergy, also called photosensitivity, occurs when the body’s immune system overreacts to sunlight exposure. Patients who are allergic to sunlight typically develop an itchy red rash on areas of the skin that were exposed to light. In rare cases, some patients may develop hives or blisters.
Patients of all skin tones (from light to dark) can develop skin allergies. It remains unclear exactly why sensitive patients develop this reaction. It is believed that light causes changes in parts of the skin that are exposed to the sun. The body then identifies this sun-altered skin as a foreign substance, the same way it would bacteria or viruses. This triggers the immune system to launch an attack, which produces symptoms of an allergic reaction.
In some cases, chemicals from products that are applied to the skin (like lotion or perfume) or chemicals in oral medications (like antibiotics or diuretics) may lead to an allergic reaction to sun exposure.
Determining If You Have a Sun Allergy
Photosensitivity is not the same as sunburn. Photosensitivity occurs when the body’s immune system reacts to light. Sunburn, on the other hand, occurs when the amount of sun or ultraviolet light exposure exceeds the ability of the body’s pigment called melanin to protect the skin.
Some of the most common types of sun allergies include polymorphous light eruption (PMLE), actinic prurigo (hereditary PMLE), photoallergic eruption, and solar urticaria (hives).
In some patients, the sensitivity to light gradually declines with subsequent exposures. If a cream, ointment, perfume, or other chemical is causing a sun allergy, patients should discontinue using the product and symptoms will subside. If a medication is causing symptoms, a healthcare professional may recommend discontinuing the medication or altering the dose. Once the offending chemical or medication is discontinued, the patient will not have allergic reactions to sunlight. Some patients may need to minimize their exposure to sunlight, but treatments, including antihistamines, hydrocortisone, phototherapy, and/or PUVA, may help relieve allergic symptoms.
Dr. Larry Jaeger is a board certified dermatologist who has a private practice in New York City and The Bronx at Advanced Dermatology Associates. Dr Lawrence Jaeger specializes in the treatment of all skin, hair and nail disorders including all skin growths and cancers.